JPH0145341B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fumigation apparatus for use with grains and other materials having poor fumigation performance.

A conventional device of this type consists of a fumigation chamber, a conveyor for supplying soybean meal, etc. into the chamber, and a hostoxin supply device installed above the conveyor.
Hostoxin is sequentially flowed down from the feeding device onto the soybean meal, etc. being transported by a conveyor, and when a predetermined amount of this mixture is stored in the fumigation chamber, the supply is stopped and the soybean meal, etc. is placed in the fumigation chamber. It is known that it was fumigated for several days,
This conventional device uses hostoxin for fumigation, and this hostoxin is expensive and has the disadvantage that fumigation in large quantities requires considerable cost.

Therefore, a silo system using cheap methyl bromide instead of expensive hostoxin was proposed. In other words, this silo system removes stored materials such as soybean meal and other powder by removing air from the top of the silo using a vacuum pump, reducing the pressure at the top to a near-vacuum state, and then blowing pressurized air from the bottom of the silo. This is a fluidization method, but with this method, the top of the silo is close to vacuum, but the bottom of the silo is under high pressure, and there is a considerable pressure difference between the top and bottom of the same silo, and this large pressure difference causes the walls of the silo to Considerable internal stress is generated in the silo, and in order to overcome this internal stress, the wall thickness must be increased, which has the disadvantage of increasing the equipment cost of the silo.

The purpose of the present invention is to provide a fumigation device that eliminates these drawbacks.The gist of the present invention is to connect a circulation pipe from the top to the bottom of a silo storing grains, etc., and to the circulation pipe, A pressurized inflow device for pressurized methyl bromide gas to flow into the lower part of the silo in a pulsed manner and a surge tank for accommodating exhaust gas from the top of the silo are interposed, and the inside of the silo is raised to above atmospheric pressure. It involves fumigation.

An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 designates a silo, and the top portion 1a of the silo 1 is equipped with an inlet 1b for introducing grains, and the lower portion 1c is provided with an outlet 1d for discharging grains.
b and the discharge port 1d have a lid or a gate to seal the inside. 2 denotes a pressurized inflow device, which includes a receiver tank 2a communicating with the lower part 1c of the silo 1 via a pipe 3a, and a compressor 2b communicating with the receiver tank 2a via a pipe 3b. It consists of a vaporizer 2c interposed in a pipe line 3c communicating between the tank 2a and the methyl bromide cylinder 4, and an on-off control valve 2d interposed in the pipe line 3a. is supplied to the receiver tank 2a where it is vaporized in the vaporizer 2c, and the compressor 2
The pressurized air from b is also supplied to the receiver tank 2a, and the gas is converted into diluted pressurized methyl bromide gas in the tank 2a, and the gas is intermittently or pulsed to the lower part 1c of the silo 1 by the intermittent opening and closing of the on-off control valve 2d. It was made to flow under pressure.

Reference numeral 5 denotes a surge tank connected to the top 1a of the silo 1 via a pipe 3d, and the volume of the tank 5 is determined according to the volume of the silo 1 and the amount of methyl bromide gas fed under pressure.

6 is a blower, 3e is a pipe connecting the surge tank 5 and the suction side of the blower 6, and 3f is the pipe 3
A pipe line 3g branches from the middle of the pipe line 3e and communicates with the discharge side of the blower 6, a pipe line 3g branches from the vicinity of the surge tank 5 of the pipe line 3e and its tip is open to the atmosphere, and a pipe line 3h indicates the pipe line 3e. 3i is the pipe line 3 which branches from near the blower and whose tip is open to the atmosphere.
shows a pipe branching from e and leading to the compressor 2b, and the pipes 3a, 3d, 3e, 3f and 3b
Alternatively, a circulation pipe was formed by pipes 3a, 3d, 3e, 3i, and 3b.

In addition, 7a, 7b, 7c, 7d, 7e, 7f, 7
g, 7h, 7i, 7j and 7k indicate on-off valves respectively inserted in the pipelines as shown.

Next, the operation of the above embodiment device will be explained.

The discharge port 1d of the silo 1 is sealed, and the inflow port 1b is opened, and a predetermined amount of soybean meal, for example, is stored in the silo 1 from the inflow port 1b, and the inflow port 1b is sealed. Thereafter, the opening/closing control valve 2d is intermittently opened and closed a predetermined number of times, and the diluted methyl bromide gas flows into the lower part of the silo 1 under pressure in a pulsed manner from the receiver tank 2a. By applying this pulsed pressurized inflow, the soybean meal is fluidized and most of the soybean meal is uniformly brought into contact with the methyl bromide gas. Then, the remaining gas is successively introduced into the surge tank 5 and stored therein. The degree to which the silo 1 is filled with methyl bromide gas is checked using concentration meters installed at the top, middle, and bottom of the silo 1, and if the silo 1 is not evenly filled, the on-off valves 7d, 7f, 7h, and 7j are activated. When the silo 1 is opened, the blower 6 is driven to circulate and reuse the surplus methyl bromide gas collected in the surge tank 5 to achieve uniform filling in the silo 1. Therefore, methyl bromide gas is effectively utilized and is economical. If it is desired to quickly achieve this filling by high-pressure pumping, the on-off valve 7h is closed, the on-off valves 7k and 7i are opened, the compressor 2b is driven, and the conduit 3i is used. Here, the surge tank 5 has the function of collecting and storing the methyl bromide gas discharged from the silo 1, and when operating by circulating the methyl bromide gas, the surge tank 5 has the function of collecting and storing the methyl bromide gas discharged from the silo 1. It has a function of suppressing the pulsating flow in the surge tank 5 and achieving stable operation of the blower 6. In this way, the inside of the surge tank 5 has a system in which the methyl bromide gas, which has been previously brought into the atmosphere at atmospheric pressure and then flows under pressure in a pulsed manner as described above, is collected via the pipe line 3d after passing between the soybean meal in the silo 1. Therefore, the top part 1 of the silo 1
a is higher than the atmospheric pressure, and the difference from the pressure in the lower part 1a is considerably smaller than in conventional silo systems, so the internal stress acting on the wall of the silo 1 is small, and the wall thickness of the wall may be thin.

After the concentration of methyl bromide gas in the silo 1 is equalized to a predetermined level, the pressurized flow of the gas is stopped, and the soybean meal is fumigated in the silo 1 for about 48 hours. After the fumigation is completed, the discharge port 1d of the silo 1 is opened, the on-off valve 7b is closed, and the on-off control valve 2d is opened intermittently to allow air to flow under pressure from the receiver tank 2a into the lower part 1c of the silo 1 in a pulsed manner. To smoothly discharge soybean meal after fumigation from a silo 1 without causing bridging.

The inside of the silo 1 can be cleaned by emptying the inside of the silo 1, pressurizing air into the lower part 1c of the silo 1 in a pulsed manner as described above, and collecting the air from the top part 1a into the surge tank 5. good.

As described above, according to the present invention, since fumigation is performed using methyl bromide gas, it is possible to perform the fumigation at a low cost, and methyl bromide gas is injected into the silo under pressure in a pulsed manner using a pressurization device to raise the inside of the silo to atmospheric pressure or higher. Because of the fumigation, the pressure inside the silo becomes higher than atmospheric pressure due to the methyl gas, and tensile stress acts on the peripheral wall of the silo.The silo is generally made of steel, and the steel has a high tensile strength. Since the silo is large, it is possible to reduce the wall thickness of the peripheral wall of the silo, thereby reducing equipment costs, and the methyl bromide gas that flows under pressure into the lower part of the silo in a pulsed manner by the surge tank can be reduced. The pulsating pulsating flow is suppressed, and thus the pressurized inflow device is able to ensure accurate pulsating pressurized inflow of methyl bromide gas into the lower part of the silo without being affected by the pulsating pulsating flow of the gas, Furthermore, it has the effect of achieving complete fumigation for grains with poor fumigation performance.

[Brief explanation of drawings]

The drawing is a flow sheet diagram of an example of the apparatus of the present invention. 1... Silo, 1a... Top part, 1c... Lower part, 2... Pressurized inflow device, 5... Surge tank.

Claims (1)

[Claims] 1. A pressurized inflow device that connects a circulation pipe from the top to the bottom of a silo in which grains, etc. are stored, and flows methyl bromide gas under pressure into the lower part of the silo into the circulation pipe; A fumigation device characterized by interposing a surge tank that accommodates exhaust gas from the top of a silo, and performing fumigation by raising the inside of the silo to atmospheric pressure or higher.